<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script type="text/javascript">
			function fun(){
				var a=1;
				var b=2;
				var c=3;
				a=b;
				b=c;
				c=a;
				
				console.log(a);
				console.log(b);
				console.log(c);
			}
			
		</script>
	</head>
	<body>
		<input type="button"value="点我" onclick="fun()"/>
	</body>
</html>
